Can't control VM boot device between SATA HDD and IDE HDD

Description

I have a VM setup with SATA HDD and later I added another virtual disk to the IDE interface as the slave to the CD-ROM. Even if the boot sequence was HDD only, VirtualBox searches for operating system on the IDE disk and then fails. Wasn't able to select which hdd to boot from from within VM configuration where we CAN select to boot from HDD or CDROM.